The last nation to form was The Federation. This was due to the Great Nation War. After the Collision and as the other three nations had formed, the south was divided. in two sides. The southeast was the Arctic Republic and the northwest were the States of the Hydran Confederation. These nations raged war for land.
The land that they were fighting for was between the border of each nation and not one nation wanted to give it up. The land being in such a climate had very fertile soil, minerals, and amazingly healthy wildlife. With the resources being scarce, there was a lot of conflict as to what side would get the land. There were even many acquisitions of stealing and tampering with machinery. With tensions so high it had only took only one riot in 4487 between workers from the Republic and the Confederation, that resulted in a few hundred casualties and several deaths, before the nations had declared war against another.
The the war between the nations raged on for a decade before the other nations had gotten involved. The Republic promising resources to the American Alliance had gotten the Americas involved in 4497 as Alliance troops had made their way into the battle. With uneasy tensions between the Alliance and New Asia over the Alliances treatment of robots in their factories the New Asian government jumped at the chance to involve themselves in the battle. The New Kingdoms remained neutral.
This war between nations would not end if there was no one being sensible in the dispute. A few leaders from each nation had soon rose up from the chaos happening around them to end the war. The group was called the Terran Unity Corps. The group was lead by Xavier Maximus and Arnold Evernia as they would use EMPs and other non-lethal methods to take out soldiers in battles. While the forces would fight, they would send their troops in to take everyone out. They shut down all sources of communication, limited resources provided, and had the New Kingdoms not provide any information to anyone.
With such a limit of technology and a major strain on their soldiers the war ended in less than 200 days as Alliance and Asian troops retreated. Their leaders impending impeachment for war crimes. The Republic and Confederation were forced to stop fighting; the Unity Corps occupied both nations and the border.
The border was destroyed and the Unity Corps took down both parties as they reformed the entire area to a federation under the Unity Corps which would soon become the Terran government. All disputes would be settled by the new government as no nation was allowed to have an army but all troops would work as one in the Federation.